The reaction of calcium ATPase with acyl phosphates is being examined to determine if this reaction goes through the same intermediate as found with ATP. Equilibrium constants for the steps of this enzyme will be investigated. The lifetime of carbonium ion and carbanion intermediates will be investigated in mixed water-trifluoroethanol-ethanol solvents in the presence of nucleophiles that react at a diffusion-controlled rate. Hydrogen bond formation between substituted phenolate anions and buffer acids will be studied spectrophotometrically in aqueous solution. General base catalysis of the reaction of pyrazole with phenyl acetate will be examined in a search for a concerted reaction mechanism. Nucleophilic reactivity toward phenyl acetates to probe the mechanisms of the enhanced reactivity of alpha-effect nucleophiles.